The use of implantable balloons in the treatment of proliferative disorders has become increasingly sophisticated in recent years, and improvements in surgical, chemotherapeutic, and brachytherapeutic techniques have led to better outcomes for patients suffering from such disorders. Treatments for these disorders often include removing a tumor through surgical resection. The surgery is then supplemented with radiation therapy whereby the residual tumor margin is targeted for treatment post resection.
Post resection radiation treatment is often referred to as “brachytherapy” and involves radiation therapy delivered by a spatially-confined source of therapeutic rays inserted into a mammalian body at or near a tumor or other proliferative tissue disease site. Due to the proximity of the radiation source, brachytherapy offers the advantage of delivering a more localized dose to the target tissue region. For example, brachytherapy can be performed by implanting radiation sources directly into the tissue to be treated. In brachytherapy, radiation doses are highest in close proximity to the radiotherapeutic source, providing a high tumor dose while sparing surrounding normal tissue. Brachytherapy is useful for treating malignant brain and breast tumors, among others and is often carried out using radioactive seeds, such as 125I or 192Ir.
In clinical practice, brachytherapy balloons are inflated after insertion in order to occupy the space previously occupied by the resected tumor and allow the radioactive seed to be inserted for the initiation of radioactive brachytherapy. Since brachytherapy devices are inflated for use, a valve is necessary for an interface between the brachytherapy device and numerous medical devices that increase gaseous pressure such as syringes, pumps and tubing that interface with inflationary devices. The valves that form the intersection between these devices may possess one-way or two-way diaphragms or actuation mechanisms. These devices are often needle free valves that permit their safe handling by health care professionals and offer the versatility to interface with various medical devices.
Early types of valve devices used multiple purpose adapters having a valve positioned in the closed position by a spring. The spring in these devices was overridden by insertion of a needleless syringe tip against the valve, overcoming the spring load thus opening the valve. These valves were then used to push fluids or gases into port systems such as brachytherapy balloons as well as bottles, vials, bags and tubing to act as a channel between the port systems. Such valve devices accommodate various uses in supplier containers and hospital settings.
The state of the art in needle-free valves are known as Luer-Activated Devices. Embodiments of the Luer-Activated Device may control a valve that prevents the outflow of fluid or gas through the connector until a standard luer connector is inserted, allowing the valve to open and fluid to be inserted or withdrawn. Three types of Luer-Activated Devices are known in the art. The first of these are capped Luer-Activated Devices requiring a cap to be attached to the valve when the valve is not in use. These types of devices are difficult to maintain aseptically because contamination can easily occur during manipulation, and the open luer connection is difficult to swab. The second type of Luer-Activated Device is the Capless Luer-Activated Device. Such devices don't require capping between uses and use positive-pressure to open and close the valve when attaching and disconnecting the valve. The third type of Luer-Activated Device is a positive fluid displacement Luer-Activated Device that is similar to the Capless Luer-Activated Device in the means by which they are used, except that they may expel fluid or gas when they are disconnected.
Valves of this nature are typically used in manufacturing sterile medical devices where they hermetically connect two volumes. A common application is the connection between inflation devices and brachytherapy balloons as well as vials, bottles, bags, tubing, needles, and syringes. During the manufacturing of these devices it is often necessary for the outlet and inlet of a valve fitting to communicate so that fluid sterilizing agents reach all surfaces of the device and the volumes they connect. Often times the sterilization procedures are aided by placing the device in a vacuum chamber to assist in drawing fluid sterilization agents into the device through the valve. When used in this manner, the configuration of a luer type device in clinical use differs because it is common for the outlet and inlet to be held closed only permitting the user to develop a differential pressure between the volumes at the outlet and the inlet. In view of this, it is evident that a manufacturer's interests to maintain the valve in an open position does not coincide with the clinician's interests to maintain the valve in a closed position. For example, when the manufacturer attempts to sterilize a closed valve device with a gaseous sterilizing agent, the agent does not reach all of the surfaces of the device. And any vacuum environment used for sterilization will cause an undesired expansion of the volume connected to the fitting outlet, which may ultimately result in the connected volume rupturing and the end user receiving a non-sterile product that may be damaged.
As discussed above, no device exists in the state of the art that compensates for this problem. The present invention solves these and other possible problems of conventional devices, and relates to a passive vent valve or adapter for use with fluid flow and administration structures for medical purposes.
Further, the present invention provides a device that fulfills both the manufacturer's interests as well as the clinician's interests by providing a self contained valve that acts both as a normally open valve during sterilization and normally closed valve during use.